Do you ever wonder what would happen if one of your patients had a vertebral artery dissection?
Do you ever wonder if you would be able to screen if your patient has a vertebral artery dissection?
We recently had a patient come through our clinic with a vertebral artery dissection and his history was alarming. Before we review this case let’s review some of the common questions about this condition:
- What is vertebral artery dissection?
- What causes vertebral artery dissection?
- How common is vertebral artery dissection?
- What are the symptoms of a vertebral artery dissection?
- How is vertebral artery dissection diagnosed?
- What is the treatment for vertebral artery dissection?
What is vertebral artery dissection?
Vertebral artery dissection (VAD) is a flap-like tear of the lining of the vertebral artery. You will remember from anatomy class that there are 4 major arteries that provide circulation to the brain, they are the left and right vertebral and carotid arteries.
When a tear occurs, blood enters the arterial wall and forms a blood clot, thickening the artery wall. This thickening often impedes blood flow and results in vertebral artery insufficiency (VBI). The clot can also break off and impede blood flow in a smaller vessel. Most commonly the lateral medulla (causes Wallenberg Syndrome) and cerebellum are affected.
Note: VBI can be caused by an arterial dissection. It can also be caused by atherosclerosis and an embolism,
What causes vertebral artery dissection?
VAD may occur after physical trauma to the neck, such as a blunt injury (i.e. traffic collision), strangulation, or after sudden neck movements (i.e. coughing). It may also happen spontaneously. Blunt trauma is the most common cause and those with connective tissue disorders are also at risk. Surprisingly, atherosclerosis does not appear to increase the risk.
Our journey, as manual therapists, with vertebral artery dissection over the past couple of decades.
In 1998, at least in Canada, there was a heightened concern with treating the neck. This was especially so in regards to manipulation and the risk of vertebral artery dissection. This heightened awareness came from an event that occurred that year in our hometown of Saskatoon, after a 20 year old died after manipulation treatment to her neck. The inquest concluded that she passed away from a tear in her vertebral artery and not the cervical manipulation itself. Regardless, the event was nothing short of tragic.
After that bedside screens were developed and became “best practice” in an attempt to reduce the chance of that happening again. Were the screens really valid? As therapists, we were all caught in the conflict of evidence vs best practice based therapy. In this case the two did not align.
Interestingly, a 1998 study found that in hospitals over a one year period, taking the correct drug and dose for the correct diagnosis resulted in 106,000 deaths in the USA. With this study it looked like there was more risk of dying in a hospital when receiving proper care than having a neck manipulation.
With vestibular therapy courses, do any of you remember being advised by the course instructor to do a VBI screen before doing the Dix-Hallpike test? It was not until taking the Vestibular Rehab course at Emory that we were reassured by one of the main course instructors that it was okay not to do VBI screening.
How common is vertebral artery dissection?
The reason the course instructor had no concerns with not doing the screens was that he knew two things:
- How uncommon the condition was.
- The bed side screening tools had poor validity. (Haldeman 2002)
So, how common is VAD? It is very rare. The overall incidence (includes carotid artery dissection) is 2.6 per 100,000 and spontaneous dissections affect all age groups, including children. They are, however, one of the most common causes of stroke (as high as 20%) in patients younger than 45 years of age. It is also worth noting that carotid artery dissection are 3-5x more common that vertebral artery dissection (source).
With manipulation, a stoke is reported to occur in 1 of 3.84 million neck manipulations. (Hurwitz 1996)
What are the symptoms of a vertebral artery dissection?
The typical patient with VAD is a young person who experiences severe headache. They then develop neurologic signs that may not appear until after several days.
When neurologic signs do occur, they are most often due to impaired blood flow to the lateral medullary dysfunction (Wallenberg syndrome) and will present as a combination of any of the following:
- Ipsilateral facial pain and numbness.
- Ipsilateral loss of taste.
- Dysarthria or hoarseness.
- Dizziness that may include vertigo.
- Nausea +/- vomiting.
- Contralateral loss of sensation to pain and temperature of the extremities and/or trunk.
- Visual field cuts.
- Unilateral hearing loss.
If blood flow is impaired to the medial medulla (rare) the following are typically found:
- Contralateral weakness or paralysis.
- Contralateral numbness.
Depending where the impaired blood flow is in the brainstem and cerebellum the following may also be present:
- Ipsilateral Horner syndrome.
- Ipsilateral diminished or absent sense of taste.
- Contralateral impairment of pain and temperature sensation in the extremities.
- Medial medullary syndrome.
- Tongue deviation to the side of the lesion.
- Ipsilateral impairment of fine touch and proprioception.
- Contralateral hemiparesis.
- Ipsilateral impairment of fine touch and proprioception.
- Internuclear ophthalmoplegia. (source)
If there is associated dizziness, there does not appear to be any specific characteristic of the dizziness (Neto 2017).
How is vertebral artery dissection diagnosed?
CT angiography and MR angiography are the diagnostic tools of choice, replacing catheter angiography, which was considered the “gold standard” test for diagnosing VAD. Carotid ultrasounds have also been used, but they provide less information and usually need confirmation with CT or MRI.
What is the treatment for vertebral artery dissection?
There are different treatment options that are be provided on a case by case basis that include:
- The use of anticoagulants, anti platelet, or thrombolysis medication.
- Angioplasty and stenting.
- Surgery in the rare case.
Case study of a recent VAD patient at North 49.
A few months ago a gentleman was referred to North 49 who had a VAD. The purpose of the referral was to address the ongoing dizziness and balance issues. Here is a brief rundown of his file.
Age: 27 years old.
Medical history: Reportedly unremarkable.
Onset of symptoms: 6 weeks prior to his visit at North 49 he started to experience right sided neck and headache pain for no apparent reason.
Initial Treatment: Was seen by his chiropractor who adjusted the neck as there was joint stiffness. His family physician prescribed pain medication. Due to increased symptoms he was seen at a local hospital four days after the onset of symptoms where CT imaging revealed a right sided vertebral artery dissection. The attending neurologist prescribed medication.
Turn for the worse: About three weeks after attending the hospital he started to experience numbness throughout the left side of his head, weakness of the left leg, and a heaviness of his chest. He also reported having dizziness with lying down and with extending his neck.
Initial exam findings:
- Alert and oriented to person, place, and time.
- Speech, demeanour, ability to provide a history, articulate and speak WNLs.
- Gait, Romberg, and single leg balance WNLs.
- There was reported and observed left sided facial weakness. Cranial nerve testing was otherwise WNLs.
- Plantar responses and ankle clonus testing WNLs.
- Upper and lower extremity deep tendon reflexes, motor strength, and light touch sensation testing WNLs.
- There was no spontaneous or gaze evoked nystagmus with and without visual fixation.
- Neck AROM was symptom free when tested to 75% of normal range (initially had restrictions in regards to how far he could move his neck).
- Dix-Hallpike and roll tests were negative.
- Joint position error testing was impaired when tested to the right.
- Progressive static and dynamic balance exercises.
- Facial exercises.
- Neck proprioception exercises.
- Monitoring of gradual return to normal activity.
Was seen for three follow-up sessions and by the last session he was back to his regular daily routine. He only had neck and facial symptoms after several hours of activity. Otherwise his symptoms had resolved.
Case study summary:
- The gentleman fits the demographics of the typical patient with this condition.
- He initially presented with findings consistent with acute neck and headache pain that mimicked that of musculoskeletal origin.
- Two different care providers from different backgrounds both thought the pain was musculoskeletal in origin.
- Would I have done anything different if this gentleman came into my office with his acute symptoms?
To answer the question we put out at the beginning of this article, “Vertebral artery dissection, is this something we still need to worry about?”, we definitely cannot say “No”. As a care provider we can be reassured that VAD is rare. When it does occur it can, however, be easily missed as it often initially presents as a typical musculoskeletal neck condition.
That being said, here are three things we can do to protect our patients:
- Take a thorough history to rule out any red flags.
- Schedule the follow-up appointment within a couple of days of the initial assessment, especially if the pain is acute.
- Use a progression of forces in treating the neck. What we mean by that is starting with posture correction. Then progressing, if needed, to patient movement, then patient movement with self over-pressure. The next level of force is therapist over-pressure, then therapist mobilization. The last, or highest level of force is manipulation. Really, and maybe it is our background training in the McKenzie Method, the best level of force to treat something is the least amount of force needed to address the physical problem.